A person working at subzero temperatures under winter conditions or staying outdoors under very cold conditions in general, e.g. in arctic areas, has to breath in great amounts of cold, dry air. This is not only unhealthy but also substantially increases the loss of heat of the person as the body tends to warm up the inhalation air to the temperature of the body and this amount of heat is removed from the body with the exhalation air. In addition, dry inhalation air has a disadvantageous effect on the normal moistness of the mucous membrane of the respiratory passages.
Various breathing masks are previously known which are intended for use when working at subzero temperatures, whereby the purpose of the mask is to enable the recovery of heat and moisture from the exhalation air and to transfer them into the inhalation air. Examples of such known masks are those disclosed in FI Patent Specifications 49241 and 52019 and FI Patent Application 895044.
In principle, the masks described in the abovementioned patent documents operate completely flawlessly, but their usability is not the best possible. One factor impairing their usability is their impractical design, as the shape of the masks deviates substantially from the shape of the wearer's face. As the mask protrudes strongly from the face, its usability is substantially deteriorated. With some of these masks, a further drawback is the great weight caused by the disadvantageous shape of the heat exchanger portion, which in some cases requires the use of a rather large mask portion.
The solution disclosed in FI Patent Application 895044 provides a considerable improvement over the solutions disclosed in the above-mentioned Patent Specifications. The only major drawback of the solution of FI Patent Application 895044 is that the cost of manufacture of the construction cannot be reduced to such an extent that it would be profitable to sell the mask as a disposable product in connection with a sports competition, for example. Another factor speaking against disposability is that the materials used in the manufacture of this breathing mask are not biodegradable, and so the disposability would cause environmental problems. The solutions described in FI Patent Specifications 49241 and 52019 have the same drawback.
The object of the invention is to provide a breathing mask by means of which the drawbacks of the prior art can be eliminated. This is achieved by means of a breathing mask of the invention, which is characterized in that the mask portion and the heat exchanger portion are made of the same material.